Allardyce, who has been absent for the team's last three games, underwent heart surgery last week and is recovering at home.

It was initially hoped he would return to the dugout for the cup tie at Ewood Park, but Allardyce is now not expected back at work until Friday, a day before Rovers host Liverpool in the Barclays Premier League.

Planning to return: Sam Allardyce

'He is at home, he's convalescing and hopefully he will be back in work on Friday,' said McDonald, who will continue to stand in for the former Bolton and Newcastle boss.

Asked whether it had been optimistic to expect Allardyce back early this week, McDonald said: 'It probably was, yes, but all you can do is take the medical advice.

'He has got through the procedure which is really good and he sounds in fantastic spirits. He can't wait to get back and hopefully Friday will be his first day back.'

So far McDonald has overseen a 2-0 win at Bolton - Blackburn's first away victory of the season - followed by a 3-0 defeat at Fulham and a goalless draw with Stoke at Ewood Park on Saturday.

Number two: Neil McDonald

Allardyce has maintained a heavy influence over team selection and decision-making during that time and McDonald said both he and the manager were feeling positive about how things were progressing in his absence.

'My phone bill is probably sky-high at the moment but that is the way it has to be,' McDonald said.

'He is the manager of the football club and we all have to keep in touch with him to see what his views are.

'He has watched the games afterwards and it has given him time to analyse everything.

'He gives us a little bit of feedback and then we have to implement whatever he wants on the training ground.

'We have done that and got a few decent results, despite not picking anything up at Fulham.

'It could have gone either way against Stoke - we could have pinched it at the end and got three points. But we have also got our first away victory since he has been away so I think it's all positive.'